Yes really. Starting 1000 ft agl at 1000 ft from the runway, and following the standard pattern, it would be 1000 ft to the turn to base, 500 on base turn, 400 on base, 500 on final turn and a 1000 for final. Total 3400 ft. opening full brakes for all this distance, at 1 on 7 you lose close to 500 feet. And you started at 1000 agl, so you are still 500 ft too high. You need more powerful brakes and flaps. But you shoudn't be using full airbrake during the whole pattern, it is better to use half.

Please check your traces on seeyou, or check how far you are from your home runway using google earth, a rough estimate is enough. You will be surprised.

I think you may be believing you fly with a 45 degree dip angle (1:1) to the runway when in fact it is more like 30 degrees (1:2). Just a matter of perception. As long as you keep it doing it like that you can call that angle 100 degrees or pi or a million, it is still safe. And if you teach somebody "this is the way it should look", that student will retain in his visual memory that angle, or slope, and it will be safe. But I am afraid of people measuring 600 feet from the runway (easy on google earth) and trying to fly a pattern at that distance next time, it is too close to the runway.

I believe you can land the Duo from 600 feet away. I don't believe you can have a real base leg when you do that.